First Peoples’ knowledge leads scientists to reveal ‘fairy circles’ and termite linyji are linked in Australia

Abstract

In the past, when scientists encountered and studied ‘new’ environmental phenomena, they rarely considered the existing knowledge of First Peoples (also known as Indigenous or Aboriginal people). The scientific debate over the regularly spaced bare patches (so-called fairy circles) in arid grasslands of Australian deserts is a case in point. Previous researchers used remote sensing, numerical modelling, aerial images and field observations to propose that fairy circles arise from plant self-organization. Here we present Australian Aboriginal art and narratives, and soil excavation data, that suggest these regularly spaced, bare and hard circles in grasslands are pavement nests occupied by Drepanotermes harvester termites. These circles, called linyji (Manyjilyjarra language) or mingkirri (Warlpiri language), have been used by Aboriginal people in their food economies and for other domestic and sacred purposes across generations. Knowledge of the linyji has been encoded in demonstration and oral transmission, ritual art and ceremony and other media. While the exact origins of the bare circles are unclear, being buried in deep time and Jukurrpa, termites need to be incorporated as key players in a larger system of interactions between soil, water and grass. Ecologically transformative feedbacks across millennia of land use and manipulation by Aboriginal people must be accounted for. We argue that the co-production of knowledge can both improve the care and management of those systems and support intergenerational learning within and across diverse cultures.

The global biogeography and environmental drivers of fairy circles

“…This is consistent with previous studies showing the importance of social insects as drivers of FC patterns in Namibia ( 8 , 38 ) but not in Australia [( 23 ); but see ref. 9 ]. Our analyses further reveal that FC-like vegetation patterns are more likely to be present in hot deserts according to the Köppen climate classification [( 39 ), SI Appendix , Fig.…”

“…The latter occurs on sandy soils with gaps surrounding vegetation patches showing higher soil moisture ( 6 ), whereas in Australian FCs, the finer soil texture induces the opposite response, i.e., higher runoff in gaps and higher infiltration under plant canopies ( 7 ). In addition, termites and ants have been found to be the main drivers of FCs in Namibia ( 8 ), but not in Australia, where the action of vegetation-water feedbacks has been proposed as the main mechanism driving the formation of FCs [( 4 ); but recent evidence suggests that termites may also play a role there, ( 9 )]. These differences, and the potential role of other factors in FC formation, such as allelopathic effects and soil nutrient deficits, have stimulated a lively scientific debate about the origin of FCs, which is conditioned mainly by the fact that so far there are only two places on Earth where these structures have been found ( 10 – 12 ).…”

Aeolian Sand Sorting and Soil Moisture in Arid Namibian Fairy Circles

“…Two main theories have been proposed to explain fairy circle development. According to the termite hypothesis, the termites eat the grass' roots in the Namibian fairy circles (NFCs), whereas the hard pavement created by the termites prevent grass growth in the Australian fairy circles (AFCs; [11][12][13][14]). The self-organizing theory views the fairy circles as one of the various vegetation patterns that form in water-limited systems due to competition between plants for water [15,16].…”

“…(NFCs), whereas the hard pavement created by the termites prevent grass growth in the Australian fairy circles (AFCs; [11][12][13][14]). The self-organizing theory views the fairy circles as one of the various vegetation patterns that form in water-limited systems due to competition between plants for water [15,16].…”

Microbial Factors May Contribute to the Persistence of Australian Fairy Circles

“…While there are multiple hypotheses for their origin, two currently prevail [7]. The fi rst attributes their formation to prepatterns formed by termite social dynamics [8][9][10][11] and the second to scale-dependent plant-water feedbacks that result in partial plant mortality and the formation of gap patterns, which, in turn, may provide habitats for termite populations [12][13][14][15][16]. Another class of processes that may possibly aff ect FC patterns, but so far has received little attention in this context, is negative plant-soil interactions, such as allelopathy and autotoxicity, which can either be direct, through the release of toxic materials, or mediated by microorgansims' phytotoxic activities [17][18][19][20].…”